I've spent a lot of time recently working on various cakes for Dinkydoodle designs working on a range of moving cakes that are headed for mass production. The Cars, Droid heads and Owl head, are all essentially the same thing, a controller and a few servos. Like most projects I work on now I started to look at the arduino range to for a controller and software, there are lots of compatible devices to suit every budget and a lot of the libraries are well established for all the basic functionality. The car needs some wireless control though which ultimately led me to the ESP8266 chips. Given my lack of recent laser cutting blogging I thought it would be sensible to share some information about this work in the hope that it might help someone else.
The ESP8266 is a low-cost Wi-Fi microchip with full TCP/IP stack and microcontroller capability produced by Shanghai-based Chinese manufacturer, Espressif Systems. Which is to say, they're capable of creating a wifi data link to your phone/laptop/other device, they can serve html web pages and a whole range of other useful things and are currently available from as low as £1.20 each. I jumped straight in and purchased a few ESP-01 devices (pictured) and waited for them to arrive. Obviously I should have done a bit more research before starting because I bought the wrong thing.
The first lesson I learnt is that there are a lot of different types of ESP chips, they've had a fair bit of development over the years and some significant improvements. There is nothing wrong with the ESP-01 device, it's the cheapest of the bunch and it's fully capable and functional but you will need a programmer for it. If like me you have a few old arduinos floating around, it's possible to wire one of those up to reprogram the device. I followed this route to stop me waiting on more parts to arrive but the two rows of pins make it a pain to put on a breadboard. If you want to use these devices I would really recommend buying a programmer especially as they only cost £0.65. But read on before doing either of those things.
The ESP-01 is an older device, it has some quirks and most notably only 4 usable GPIO pins. The ESP12 is the much more recent device and has 9 GPIO pins, it's also available for the same price per module. As you'll notice from the image though it's not particularly breadboard friendly. If you're incorporating it into your own pcb you can treat it like any other smt device but for quick start you're probably better off buying it already built into a development module. I ended up going with the Wemos D1 Mini which you can get for <£2.00 a time and it has the Serial device built into it. The whole thing can be powered off USB and it's relatively easy to attach your own things to it.
The ESP12 also comes in a range of different boards, the wemos typically comes with ESP12f but Espressif seem to be up to ESP12n, from my view point I've not seen a notable difference between them but newer is probably better right? This website offers a fairly comprehensive review of all the different modules, modes and boards that you can get the ESP devices in. Next up, I'll talk about getting started and the infamous blink led sketch.